Automatic safety pilot



March 29, 1949. R. E. NEWELL 1 AUTOMATIC SAFETY PILO'l Filed Dec. 11,1945' Fig.1

Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE Claims.

This invention relates to flame responsive-cutoff valves forautomatically closing a main gas supply to a heating burner, and also toa pilot burner, in the event that said pilot burner is extinguished, theoperation being termed a one hundred per cent cut-off.

The particular type of device herein described is generally referred toin the art as a pushbutton safety pilot, in which the main cut-off valveis manually pushed open and is latched, or otherwise held open, by athermally operated mechanism responsive to a pilot flame.

In controls of this character the valve may be held open at a pointgiving large capacity, and closed with a relatively strong spring, soare preferable for large Water heaters, furnaces, ovens, etc. Howevervalves of this type have been characterized by certain disadvantages, toovercome which it is the purpose of this invention:

First, to provide such a valve in a rugged design. with no externaloperating parts susceptible to damage.

Second, to insure a quick and positive operation to hold the valve openwhen the pilot is lighted, and to close the valve almost immediatelywhen the pilot is extinguished, regardless of ambient temperatures.

Third, to provide such a valve, having a mechanically operated thermalelement, with a wide and powerful closing movement, without imposingfriction, load or strain on its thermal element while the thermalelement is heated by the pilot flame.

Fourth, to provide manually operated valve opening means which is selfreturning to normal position while the valve is latched in openposition, whereby the automatic closing of the valve will not behindered or prevented by friction of sliding or bending parts in themanually operated valve opening means.

Fifth, to provide an automatic safety pilot having a mechanicallyoperated thermal element installed adjacent to a main burner, with anindependent pilot gas supply, and means for closing same automaticallyand simultaneously with the closing of the main gas supply.

Sixth, to provide a manually operative unit for a one hundred per centcut-off, with means permittin opening of the pilot supply line first,without opening the gas supply to the main burner, and to hold saidpilot supply open automatically while the pilot is being lighted and thethermal element is being heated, prior to opening of the main gassupply.

Seventh, to provide for the operation of said control, a rod-and-tubetype thermal element having an internal rod adapted to move laterallyinstead of endwise, by thermal expansion of the tube, and meanspermitting an external adjustment of the internal rod by rotation of thetube.

Referring to the drawings:

Fig. 1 is a section view of the entire control.

Fig. 2 is a section on the line X--X, Fig. 1.

Fig. 3 is an external side view of the thermal tube and pilot burner.

Fig. 4 is an external view of the outer end of the push button assembly.

Fig. 5 is a section of the middle portion of the control, with the valveparts in a different position from that indicated in Fig. 1,

The main body of the control is indicated in Fig. 1 by the numeral I.The valve closure member 2 is urged toward its closed position on valveseat 3 by sprin 4. 5 is a screw cap, conveniently removable for accessto the valve parts within the body I.

The body I is provided with a main gas passage through a chamber 6 thathas an inlet 6a, and through a chamber 1 that has an outlet 8. Bothinlet and outlet are threaded for connections to other controls and to amain heating burner, not shown.

9 is a detachable push button assembly or manual operating unit,adapting the control to operate as a one hundred per cent cut-off. It isattached to the control by means of a flange Ill, secured by screws II,which are threaded into a boss i2, extending from the control body I.Between the flange Ill and boss l2 a diaphragm I3 is inserted for a gasseal, and also as a second valve closure member.

Pilot burner 14 is provided with ports l5 (as shown in Figs. 2 and 3),adapted to progagate a continuous flame or series of flames [6 whichimpingeupon one side only of thermal tube H, as indicated in Figures 1and 2.

Figure 2 illustrates how the flame l6 encircles and heats approximatelyhalf of the circumference of the tube H, the opposite side of the tubereceiving heat only by conduction. The tube is made of a chromium-nickelalloy having a low heat conductivity and therefore its opposite side isof substantially lower temperature.

This differential in temperature causes a lateral flexing action of thetube H in very quick response to the flame, as described in my priorapplication Serial No. 572,701, filed January 13, 1945, now Patent No,2,426,786, granted September 2, 1947.

I8, Figure 1, represents an operating arm, rigidly secured to the outerend of the tube 11, said outer end beng closed gas tight. The oppositeor open end of the tube 57 is screwed into a boss it in the body I, thefree end of the arm i8 extending through the open end of the tube intothe gas outlet chamber '1. On the free end of the arm IS a smallcircular cam 20 is provided by welding same on the end of arm l8,slightly off center.

A triggeril ,preferably a sheet-metal stamping, is located in the outletchamber '1, of the gas passage through body i. The trigger 2! is pivotedat 22 in a trigger support member 23, said trigger support member beingmachined iroma square brass bar, with a reduced round portion at eachend, one end being inserted thru a central. hole in the body 1 andriveted asshownat 24.

A flat spring 25 is soldered orotherwise secured at its lower end to theflat side of member 123,

extending between member 23 and trigger 2 l, and passing through a holein trigger 2!. The

tension of .thisflat sprin is .to ,normally urge the ,upper endofsaidtrigger .21 to the left, thereby pushed open by means of the valvestem28, which is actuated through the .push button 2& in a manner laterexplained.

When the notch 21 in the valve stem 28 is in a position to be latchedand held toopen position "by'the-trigger 2|, the .parts will beas shownin While the pilotflame It remains lighted .Fignl. theparts ,will remainin this. position.

l-Iowever, should the pilot flame become ex- ,tinguished the .tube ,I'lwill flex to its normal straight position, swinging the arm l8 in-amanner causing the cam 20 to engage one arm of trigger 2| rockingtheupper end-of the trigger out of the notch .21, of the valvestem, asindi cated by dotted lines, thus tripping the .main valvetoclosedposition.

Thisactionwill take place in a matter of six to eight seconds from thetime the flame isextinguished, regardless of the ambient temperaturesurroundingtube I1.

As previously mentioned, the flame l6 encircles and impinges onapproximately half of the circumferential surface of the tube ll. Themidpoint of the flame is in aplane corresponding to the action oftrigger 2|, and the axis of valve push rod ,28. It is in this plane thatthe outer end of tube I! is flexed by the action of flame I 6, saidflexing ofthe tube, ina direction away from the flame l6,,causing thefree end of the arm 18, and cam 20, to move in the opposite direction,disengaging the cam 20 from trigger 2|. When the flame is extinguished areverse action takes place; the trigger is engaged by cam .20, and thevalve is tripped to closed position, as above described.

The purpose of cam 20 is to obtain a convenient external adjustment ofthe thermal mechanism with relation to trigger 2|. This is accomplishedby simply rotating tube H in one direction or the other, whichactionalso rotates the arm l8 and cam 28, thus chang g :its rela- 1 101to trigger 2|.

,By the above described arrangement all operating parts are entirelyenclosed, making it unnecessary for the comparatively delicate thermalaction .to be transmitted through packing pins,

,lyusedon an appliance. .type the maincut-ofi valve inthe pilot controlis used to also cut off the pilot supply gas.

" sheet brass.

etc., and obtaining a positive release of the valve with the leastpossible friction.

It will also be noted that since the cam 20 is out of engagement withthe trigger 2! when the tube H is in its heated condition, there is noload whatever upon the arm l8 when the tube I I is so heated. Much ofthe failure of pilot control devices heretofore, has been due to thethermal element being loaded when hot, for long periods of time.

'It is desirable that an automatic safety pilot shut off the gas to thepilot flame as well as to .the main burner, especially where theappliance .on whichit is used has no outside flue connection,

or where bottled gas is used, which is highly explosive.

Heretofore this feature has been available only on thermocouple typepilot controls which may beinstzalled remote from the burner on theinlet side of the main gas cook and thermostat, usual- In safety pilotsof this However, .in the present device, which must :be installedadjacent to the main burner, I provide an independent pilot gas supplyand a second valve, to cut off the pilot gas supply, thus making itpossible to provide a one hundred per cent cut oil on a pilot controlhaving a mechanically operatedthermal element, and installed adjacenttheburner, on the outlet side of any thermostator .maingas cock used in thegas line, it being necessary only to connect the pilot gas supply to .apoint ahead of the thermostat.

.I will now proceed to describe the manner in whichthis is accomplished.

Referring to Fig. 1, the flexible diaphragml 3 is preferably made ofsynthetic rubber or of thin It is moulded or pressed to aconcave-convexform permitting wide movement at its center. At its outer periphery itis flat,,-and serves as a gasket seal.

.Atthecenter of diaphragm [3 a button 31 ,-is

provided, which maybe'either molded in the vdiaphragmo-r be made-ofmetal, as indicated, the purpose being to provide a flat rigid-area atthe center of the diaphragm to render it suitable as a valve closuremember. Thebodyportion 3a is recessed at 32 toprovide spaceforthemovement of the diaphragm I 3. ,At its-center a valve seat 33 isformed, communicating with a central bore 34, having a flat bottom, and.from which a:smaller hole continues through the center of the .bodyr3fl.

.Slidably mountedat the outer end of thebody 3B is thebefore-mentionedpush button 29.in.-the form of a hollow cup, and having ,riveted at itscenter around rod 35 whichextendsthrough-into the bore 34 of the body30.

. A ;-retracting spring 36,; mounte d,in the body13 0,

normally tendsto urge the push :button 29 toward its outward position.Thepush button :29 islimited in this outward movement-by a rubber collar31, which is forced over-the rod 35 and into the reduced portion .38ofthe rod 35 before gitis assembled andrivetedto the push button 29. A gasconnection is madetothebody'3ll;at39 permitting gas to enter the bore,34. Thisgasis supplied through-a line, (not shown) connected to th maingas supply .at a po nt bef re any thermostat or main gas ,cock ;is used,{and :is supp dto the pi t burner 114, through the present controlvalve, independently .Qf the main gassupply, aswill now b e;describ.ed.

With the main valve closure member 2 and diaphragm l 3 in the positionshown in Fig. 1, gas passes from the bore 34 into the recess 32, fromwhence (see Fig. 5) it passes through small hole 40, through aregistering hole 4| in the diaphragm l3, into hole 42 in the maincontrol body I, connecting with the pilot burner l4, which extends fromthe boss I9 of body I, as shown in Fig. 3. The tapped hole in which thepilot tube I4 is inserted connects directly with hole 42, Fig. 5..

The lower end of valve stem 28, Fig. 1, has an axial bore in which isinserted a light spring 43 and a yieldable pintle 44, the pintle beingheld in by. spinning or pressing over the end of stem 28. The purpose ofthis yieldable pintle 44 will presently be explained in the descriptionof operation of the control device.

Operation Should the pilot flame I6 be extinguished the immediateflexing of the tube I! to its normal straight position, and theconsequent movement of the free end of operating arm l8, Fig. 1, to theposition shown by dotted lines, will operate the trigger 2| to trip thevalve 2 to closed position.

As the valve 2 moves toward closed position the lower end of stem 28 isforced down so that the pintle 44 at the lower end of stem 28 engagesthe button 3| at the center of the diaphragm I3, moving the diaphragm tothe position shown in dotted lines I3a, where it contacts the seat 33,thus closing the passage of pilot gas from the bore 34 to the pilotburner l4.

At this point the pintle 44 yields, slightly compressing the smallspring 43, by the force of the stronger main valve closing spring 4, sothat the stem 28 continues to move downward slightly, allowing the mainvalve closure member 2 to close completely. Thus both the main gassupply to the main burner (not shown) and the pilot gas supply iscompletely out off at practically the same instant.

To relight, the operator first pushes the button 29 inwardly and turnsit clockwise to the right so that pin 45, which is fixed in the body 30enters the off-set slot 46 (Fig. 4) of the push button, where it is heldby the outward pressure of the retracting spring 36 against the pushbutton 29. The hand of the operator may then be removed from the pushbutton 29, as it will remain in this position, at point B, Fig. 4. As aconsequence of this slight inward movement of the push button the rod 35has moved inwardly as shown in Fig. 5, so that the diaphragm is slightlylifted oiT the seat 33, permitting pilot gas to pass through to burner I4, in a manner already described. This slight upward movement of thediaphragm causes the pintle 44 to yield further, but, as beforeexplained, due to the stronger spring 4 the main valve is held closed.

After the pilot is lighted, and a few seconds allowed for the thermalelement to act to permit movement of the trigger 2| by the spring 25,the push button 29 is turned to the left (counter clockwise) out of theoff-set slot 46 and pushed on inwardly so that the pin is in the slot atthe point 41 and the push button is at position C shown in Fig. 4. Withthe push button 29 in this position the inner end of the rod 35 willhave forced the diaphragm l3 upward, so that, looking at Fig. 1, it isin the position shown by the dotted lines 13b. This action of courseforces the stem 28 and main valve disc 2 to open position where it islatched by the trigger M.

The push button 29 may then be released, whereupon. it will return tothe position A shown in Figures 1 and 4, the pin traveling, relativelyspeaking, up the slot in the push button and around to its originalposition. The valve and other parts will of course remain in thisposition as long as the pilot burner is lighted. It may be noted thatthe entire lighting operation may be performed with one hand.

It should also be noted that should the push button 29 be accidentallyforced in it will be stopped by the pin. 45 at position B; atv whichpoint only the pilot gas will pass to burner l4, and

the main valve will not be opened. As soon as such accidental pressureagainst the push button 29 is released it will return to its outermostposition A and the pilot gas will again be cut oif as before explained.

It will be noted that the main valve is easily removed for cleaning;also the stem 28.

The stem 28 is a loose fit in trigger support 23 so there is nopossibility of its sticking.

The trigger support 23 together with the trigger, 2!, may be easilyinserted through the opening of the main valve, in assembling.

Neither the stem 28 nor the rod 35 are tied in with the diaphragm, butengage it freely, without binding.

The valve seat 33 is made easily accessible by removing the screws I land the body 30.

The rubber collar 31, seating at the bottom of bore 34 insures aperfectly gas tight closure, regardless of the lit of the rod 35 in thebody 30.

I claim:

1. A safety pilot control for gas including a body portion having a maingas passage comprising two chambers therein that respectively have inletand outlet openings, 'a valve seat with an opening therethroughpositioned between the chambers, a valve closure member co-operatingwith said seat, a spring normally urging said valve closure member toclosed position, a push rod engaging said valve closure member, manuallyoperated means for actuating said push rod to open said valve closuremember against the action of said spring, a latch-supporting memberwithin said gas passage and rigidly secured to said body, saidlatch-supporting member having ing adapted to hold and release said pushrod to thereby hold said valve closure member open or to release it formovement to closed position, said body being provided with an openingadjacent said trigger, a hollow thermal member extending from the bodyin line with said opening and communicating with the opening, saidhollow member being closed at its outer end, an operating arm withinsaid hollow thermal member having one end secured to the outer or closedend of said hollow thermal member and its opposite or free endpositioned to engage said trigger, and a pilot burner secured to saidbody in fixed relation to said hollow thermal member and provided withports adapted to propagate a flame to heat one side only of said hollowthermal member, causing said member to flex laterally at its outer end,and to thereby actuate said operating arm and trigger in a planecorresponding to said flexing action.

2. A flame responsive control for gaseous fuels including a housing, amain gas passage through said housing, a valve seat and valve closuremember in said gas passage to close off the flow of gas therethrough, aspring yieldably urging the valve.-

;.closure member :to its seat, :rmanual umeans tex- ;ternally ,operated:foreopening said valve:closure member against :1the;spring..pressure,latching mechanism within :said .gas :passage :for holding '-:-saidwaive :closure .member in open position,

-.:therma1iy operated means :adapted to (trip :said

"latching mechanism--;-upon the extinguishment :of :a pilot flame, saidithermal mechanism icomprising a tubular element secured ;.to :saidmousin :and projecting therefrom, with its outer ,end closed.andsupporting an :internal operating arm extending into :said housingand engaging :said llatching mechanism, ameans for propagating a :pilot:flame in 1a manner-to heat one 'side only 10f said tube to cause it .to:flexrat. its .outer tend-and .zto actuatersaid internal :arm in :alateral :direc- ;tion .rrelative to the axis of said .tube,:andta.latchoperating device mounted onitheifree endiofrsaid operating arm:and adjustable radially "roilthe tube.

3. A :flain-e'iresponsive :controlfor gaseous 1 1 11618 including.ahousing, amain ;gas passage through said housing, a valveiseat andvalveclosurexmemleer insaid gas passage to closeofi theflow :ofvgastherethrougnarspringfor moving the saidmemher to closed ;position, .apush :rod Within :said housing at or manually opening said valve:closure member against the valve closing spring, aitrigl ger supportmember'rigidly secured within said housing, a trigger pivotally'supported by ;said :member, a spring :adapted to rock said trigger intoengagement with said push :rod, ,to hold said push rodand said valveclosure member in open position, a tubular thermally responsiveeleillfilll', extending iromsaidhousingadapted to be z laterally flexedby the impingement upon .onezside thereof of a.;pi1ot flame, meanspropagating :a pilot flame in contact with said element-in -a ,manner todirectly heat one side only, itoecause said element to flex inaegivenplane, and in'a direction away'from-said flame, an operating :arm,secnred .at the outer endaofsaid elementrandiextending within the same,to a,point within said housing, :said operating arm being adapted :tomove laterally within said tubular :element in one direction with theflexing of -;said tubular ielement in-t'he presence of said pilotflame:and to return to a normal position upon rthe'iexitinguishment of saidpilot flame, :a tripping ele- .ment ontheend ofsaid operating arm,withinasaid :housing, and positioned to engage said tri ger, andmeansfor adjusting said-arm to :shiit :the tripping element in a:directionnormal to the axis ,ofpsaidypush rodto effect release-of saidzrodand-:said-valve closure member. for movement-toclosed position as saidoperating arm approaches ,its 'normal position, after *extinguishment ofsaid pilot-flame.

.4. A safety pilot control ior ga-s including a :body -portion providedwith apassageway having agas inlet and ages outlet, 2a valverseatbetween :said .inlet and outlet, pr0vided with an opening :therethrough,a 'valveiclosure rnemberon one ,side ioi .said opening -;adapted tocooperate with ,said

seat, a closing-spring -normally ,urginB said valve closure .member toclosed :position, "a manually operable :stem :on :the opposite .side of:said valve opening adapted to contact :said valve closure memberand toopen it against the :actiomof said spring and having a latch-engagingshoulder, a

latching mechanism :comprisinga trigger, ,a trigger spring, :and asupport membenhaving'a :cen- *tral bore :for said .-stem,.:means for'pivotally sup- :porting :the trigger and :thetriggerspring on the*supporting izmember, ;said ,:latchin g mechanism .tbeing of :smallerdiameter than .the \valve rseat anpening,iwherebyiinmaybelnserteiiithroughesai'd :va'lve ;opening' and secured rto: said valve:bodyson :the side :of :said waive iopening opposite "to :said 5iolosure member, .anda zhollow thermal tube rclosedzatzits :outer :end,extending .from said-body, and Lihaving fan internal operating arm:responsive iniits movement to :the thermal :action .:of:said:.tube,,-saidanmsextending within saidzbody :on the side of said valveopening :opposite to .saidwalve :olosure member, and; adapted.toimovessaid trigger gout :oii +.engagement with said manually :operablestem, against the :tension of :said trigger spring, whemsaid thermaltube is .inan unheated-condition, and ;t.o;move t ...l ermit:returnofsaiditrigger, .by the trigger :Zspring, into en agement wiithjsaidmanually operable valve-opening stem, toflatch said valve closure memberin open position, when said thermal tube isin a heated condition.

990 5. A safety pilot control for gaseous fuelsinlzcludingia;body;provided with a :main jgasipassage, :amain valveadapted to cut oil the gaspassing :throughsaid-body,avalve-closing.springmmanually operated stemforopeningsaidvalve againstthe pressure of the valve closing spring, a ;piv,ot,ed trigger ion thebody I, for releasably latching the valve 1Qr en,;a;light-.springnormally :urging ,said tri ger into engagement with shoulder --on .saidrstcrn tohol'd said main valve in opengposition, themovement OfiSElidtrigger being limitedibyzits engagement-with said-steam, a thermalelement comprising a hollow tube extending outwardly .ir om,-said-body,'with its inner end inlflxed relation to said trigger, burner portmeans in fixed relation toisaid tube and adapted Ito propagate aflame toheat one side of said tube-only, adjacentits outer end portion, therebycausing .said outwardlyextending, portion to flex laterally out ofalignment with-its-normal aXis,-and-zan operatiingrarmsecuredltothe-said tube at a point remote from said innerlend and extending backinto'sald body, its free .end being positioned .to-engage said triggerwhen said tube is cold, to holdsaid-trigger tout ofrengagement with saidstem, thetotal movement of said when the said tubeiszheated flexed toits maximum point being substantially greater than the limited movementof the trigger, whereby said arm may disengage itself .from said triggerand thus free itself of the load -.developed by the tension of thetrigger-while said tube is in its heated condition. .6. An automaticsafety control forgasinclud- 'illg a \body member, a control "member.mounted therein, thermal mechanism for operating said control member,said thermal mechanism being responsive to the heat of a name, andcomprising a .rotatably mounted tube extending from the 'bodymember inwhich said control member is situated, an operating arm secured to theouter end of said tube and extending lengthwise within said tube to aposition adjacent said control lmember, .cam means connected to thefreeend of said operating arm and .operatively associated with said controlmember, and adapted to .be adjusted relative to said control member byroatation of said tube, and a pilot burner having ,port means adapted todirect a heating flame in a manner to heat one side only of said tube,to ,cause-it toflex and consequently to move the free .end of saidoperating arm laterally within said .tube, in "a given plane, wherebysaid arm and cam means Will operate said control member in accordancewith the presence or absence of said .heating flame.

7. A control :device including a control memher, a thermally responsivemechanism, a lever between said control member and thermal mechanism fortransmitting the action of said thermal mechanism to said controlmember, said thermal mechanism including an operatin arm provided with acam at one end to engage said lever, and secured at its opposite end toa thermal tube mounted in said control device and projecting therefrom,the tube and the arm being rotatably adjustable as a unit, whereby theadjustment of said cam relative to said lever may be varied, and meansfor applying heat to one side only of said thermal tube to cause it toflex in a given direction at all adjusted positions of the tube, and toactuate said arm and cam in a lateral direction relative to said tube,thereby effecting operation of said lever and said control member inresponse to the application or removal of heat from said thermal tube.

8. A flame responsive automatic pilot valve for cuttin off the fuelsupply to both a main heating burner and an independent pilot burner,including a housing provided with a passageway having a gas inlet,having a gas outlet to said main heating burner, and also havingindependent gas passages connecting to a pilot burner, a first valve inthe main gas passage through said housing, a sprin yieldably urging thevalve toward closed position, a second valve in the independent gaspassage connecting with said pilot burner, said valves being operativelyconnected, an external actuating member adapted to first open saidsecond valve to admit gas to said pilot burner, and then to open saidfirst valve to admit gas to said main heating burner, means responsiveto the flame of said pilot burner adapted to retain said first valve inopen position while said pilot flame is burning, and to release saidvalve when the pilot flame is extinguished, and yieldable connectingmeans between the first and second valve for closing the second valveduring the movement of the first valve toward its closed position, thesaid first valve closing immediately after said second valve has becomeclosed.

9. A flame responsive automatic gas cut off control adapted to cut offthe fuel supply to both a main heating burner and a pilot burner,including a housing having a main gas passage and a pilot gas passage, agas seal dividing said passages one from the other, a main valve in themain gas passage, a main valve closing spring, thermal operated meansresponsive to the heat of a pilot flame adapted to hold said main valveopen or release it for closing, a second valve in the pilot gas passage,means operatively connecting said main valve with said second valve, andoperating through said gas seal to effect closing of said second valveby the closing action of said main valve, manual means, externallyoperated, for opening said second valve to admit gas to said pilotpassage only, and means effec tive upon further movement of said manualmeans to open said main valve and thus supply gas to a main burner.

10. A flame responsive control for gaseous fuels including a housing, amain gas passage through said housing, a valve seat and valve closuremember in said gas passage to cut off the flow of gas through saidpassage, a spring urging the closure member to its seat, a push rodsupported at one end on said valve closure member, a manually operablemember engageable with said rod, to force said valve closure member toopen position by manual movement of the manually-operable member in onedirection, a pilot burner adapted to propagate a pilot flame, thermalmeans responsive to said flame, latching means operated by said thermalmeans and adapted to hold said push rod and valve closure member in openposition while said pilot flame is burning and to release said push rodto permit automatic return of said valve closure member to closedposition, when said pilot flame is extinguished, and a retracting springacting upon said operating member to immediately return it to its formerposition upon release thereof by the operator, after the valve closuremember has become latched in open position, whereby the said operatingmember will not impede the return of said valve closure member to closedposition upon release of the latching means.

ROBERT E. NEWELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,906,868 Mustee May 2, 19331,943,045 TePas Jan. 9, 1934 2,011,111 Mantz Aug. 13, 1935 2,023,640Morrow Dec. 10, 1935 2,363,525 Higley et al Nov. 28, 1944

